But his fight for justice ended abruptly on Tuesday night when he died at home in the eastern Indian state of Odisha, apparently of natural causes, three years after traffickers chopped off his right hand for trying to escape debt bondage.

Dhangdamajhi's story of abuse made national headlines, raising public awareness of the exploitation of migrant labourers and inspiring many with his determination to seek justice, activists said.

In 2014, the Supreme Court intervened in his case, asking the Odisha government to fast track charges against his traffickers and to provide rehabilitation for Dhangdamajhi and his friend Dayalu, whose hand was also cut off.

Confirming his death in his village in Kalahandi district, police inspector Sameer Kumar Rout of the Jaipatna police station said Dhangdamaji had been ill with a fever for a few days before he died.

His friend Dayalu told the Thomson Reuters Foundation that the family probably didn't have enough money for treatment.

Authorities have freed around 282,000 bonded labourers in 18 states across 172 districts in India since 1978.

The labour ministry said in a recent statement there was "no correct estimation of the extent of bondage", but local authorities say they get calls every week on a helpline.

Dhangdamajhi was 32 when he took a loan of 14,000 rupees ($209) from a labour agent and agreed to work at a brick kiln in 2013. He was one of the 12 labourers who had taken money from Parvesh Duni, the main accused in the case.

"At the last minute, they told us that we would have to go to Andhra Pradesh instead of Chattisgarh as promised. We suspected foul play," Dhangdamajhi told the Thomson Reuters Foundation in an interview in August.

"Most escaped en route," the father of two said. "Ten escaped but they found Dayalu and me."

The two men were taken to a paddy field, kept under house arrest and made to work, he said. The traffickers demanded that they pay back the advance taken by all 12 labourers if they wanted to go back home.

Dayalu, who was 17 years old at the time and today wears a long scarf even in summer to hide his severed limb, said: "We didn't have 200,000 rupees and asked for some time. But one night, they took us to a nearby forest and asked us if we wanted our hands chopped or our legs."

The traffickers then decided to cut "the hands that had taken the loans", he said.

The two men survived and vowed to take on the traffickers, who operated in the guise of labour agents in the drought-prone regions of western Odisha.

Unusually for many trapped in debt bondage, they went to police, pressed charges and attended all hearings in court.

"Nilamber's testimony in court was very powerful and we are confident we will win," said prosecutor Dhirendra Nath Patra. "It will be a big win for so many who have been forced into bondage."

Of the nine accused, two are in jail and one is still at large. The others are out on bail, including the agent who first approached Dhangdamajhi and lives barely 200 meters from his house.

"Nilamber had wanted it to end quickly but he didn't survive long enough for the final verdict," Dayalu said. "I will have to see it till the end alone now."